Breadboard is an Elixir library developed to breadboarding with a single-board computer as simple as possible (this is the initial purpose).
All started using Circuits.GPIO on an OrangePi PC board, all work fine but use GPIOs is not simple beacause of the logical pin numeration.
For example work on the pin 12 in the develop machine (without GPIOs) and in the OrangePi PC (pin label PD14) imply work in different way because in the board may be open the logical pin 110 in the sysfs user space !
Starting from here the idea to try to simplify the access to pinout information.
The module to manage the pinout information for the supported platform is Breadboard.Pinout
Any pin is identify by the pin number, a pin key, a pin label and the pin name.
As example the pin 12 can be referenced by the pin number or the pin key:
Breadboard.Pinout.label_to_pin(12)
Breadboard.Pinout.label_to_pin(:pin12)
for any platform in a trasparent way, but the return value change from 12 to 110 according to the defined platform.
Same result can be obtained using the pin name or the pin label for the stub platform:
Breadboard.Pinout.label_to_pin("GPIO12")
Breadboard.Pinout.label_to_pin(:gpio12)
and for the specific OrangePi PC board:
Breadboard.Pinout.label_to_pin("PD14")
Breadboard.Pinout.label_to_pin(:pd14)
In a reverse way the pin label may be find by the Breadboard.Pinout.label_to_pin/1 method:
Breadboard.Pinout.pin_to_label(12)
Breadboard.Pinout.pin_to_label(:pin12)
produce the :gpio12 or :pd14 based on the configured platform.
In order to semplify the integration of other platform pinout mapping two module are defined to expand the Breadboard library: Breadboard.GPIO.BaseGPIO and Breadboard.GPIO.BaseGPIOHelper.
Module documentation explain also how GPIOs pinout mapping is made for a specific platform.
The first module develop to play on GPIOs is the Breadboard.Switch module.
This module handle the feature of Circuits.GPIO to manage the operation on GPIOs with the support of Breadboard.Pinout:
iex> {:ok, switch} = Breadboard.Switch.connect([pin: :gpio18, direction: :output])
iex> 18 = Breadboard.Switch.pin_number(switch)
iex> Breadboard.Switch.turn_on(switch)
iex> 1 = Breadboard.Switch.get_value(switch)
Check the Breadboard.Switch module documentation for more information.
The first module develop to play with I2C interface is Breadboard.Joystick, a simple module to manage an analog joystick connected to an 'ADS1115' analog to digital converter.
It is a very minimal module to test the I2C interface with Circuits.I2C and ADS1115 library
A simple integration is made by a dedicated test available in test suite with the specific tag integration_sunxi_joystick.
Circuits.GPIO supports a "stub" hardware abstraction layer on platforms without GPIO support but as dependecy project this feature may not be present.
It's possible to enable the "stub" on Linux by setting CIRCUITS_MIX_ENV environment variable to test.
Specific platform test are 'tagged' in order to execute, by default, only the test on the corrispondent platform.
Into the module documentation a check on platform is performed to exclude inappropriate test on different platform.
More details in the project test files and the example explained in the module documentation.
The platform is identified by the "breadboard_platform" environment variable as explained in the Breadboard module.
This value is used to map the pins for the specific plaform.
Platform supported are:
- stub -> a "stub" hardware abstraction layer as defined in
Circuits.GPIO - sunxi -> the family of ARM SoCs from Allwinner Technology
The breadboard package can be installed by adding breadboard to your list of dependencies in mix.exs:
def deps do
[
{:breadboard, "~> 0.0.6"}
]
endDocumentation is generated with ExDoc and published on HexDocs/breadboard.
Copyright © 2020 Enrico Rivarola
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
https://spdx.org/licenses/Apache-2.0.html
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
The license described above applies to the Breadboard library source as a whole.
Individual files contain the following tag instead of the full license text:
SPDX-License-Identifier: Apache-2.0
Use SPDX short-form identifiers enables machine reading/processing of software information as defined in Software Package Data Exchange® (SPDX®)
Check NOTICE and LICENSE project files for more detailed information.
SPDX-License-Identifier: Apache-2.0